retaliatory action from the united states. monday, president obama warned the syrian regime. >> i want to make it clear to assad and those under his command, the world is watching. the use of chemical weapons is and would be totally unacceptable. >> reporter: obama administration and military officials say they believe president assad has gotten the message. >> we have sent an unmistakable message that this would cross a red line. and those responsible would be held to account. >> reporter: the syrian regime, which has been massacring citizens for nearly two-straight years, has been careful not to confirm it has the weapons. >> even if we have them, we shall not use them against our people. >> reporter: but president assad's father used chemical weapons. and officials believe pressure on the current government is mounting. opposition is making tactical gains that could trigger a shift in the conflict. the state department believes the conflict is growing closer to assad and is looking into reports that assad's men are looking for a place to go into exile. >> tahman bradley, live in washington.